Abstract

The relation of the structure of the retina to factors influencing visual acuity is examined in some detail. Dimensions of the foveal cones have been redetermined in a series of measurements on histological materials from several sources. In no case has center to center distance between the most central cones in adult human eyes been found less than 2.0μ nor greater than 2.3μ, these being values for the living eye, due allowance being made for shrinkage of the preparations. Photomicrographs of the central foveal mosaic are shown to illustrate the rapid increase in center to center distance between cones a short distance from the small central fovea. These results are in general agreement with those of Polyak. This cone mosaic is in good accord with the observed effect on resolution acuity of the particular location of the image within the fovea. The central cones are of such size that the optical system of the eye at optimum pupil concentrates approximately three-quarters of the energy of a star image into a circle containing three cones, but some additional optical mechanism must exist in the retina to prevent loss of this image quality by spread of rays after the focus, but within the retinal depth represented by the length of the cones. Optical processes occurring within the cones are considered in detail. It is shown that not only is the Stiles and Crawford effect explained quantitatively by these processes, but also that the spread of rays beyond the focus is prevented, so that the retinal mosaic can behave as though the light receptors were concentrated in the focal plane. This same process also makes possible greatly increased light absorption per unit weight of cone pigment. The structure of the retina is thus consistent, numerically, with resolution acuity at high illumination but does not account for observed changes in acuity as retinal illumination is reduced. Ballistic stimulation of 10 microsecond duration eliminates effect of eye movements and serves to test both the Hecht theory of change of acuity with luminance, and the alternate hypothesis that very few quanta are absorbed per cone at threshold, statistical variation in this number accounting for the acuity change. The result of these experiments indicates that neither theory can be accepted.

© 1951 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. P. W. Cobb, Am. J. Physiol. 36, 335 (1915).
  2. S. Hecht, J. Gen Physiol. 11, 255 (1928).
  3. L. A. Jones and G. Higgins, J. Opt. Soc. Am. 37, 217 (1947).
    [Crossref] [PubMed]
  4. W. D. Zoethout, Pysiological Optics (Professional Press, Chicago, 1927).
  5. S. Polyak, The Retina (University of Chicago Press, Chicago, 1941).
  6. H. Hartridge, Recent Advances in the Physiology of Vision (The Blakiston Company, Philadelphia, 1950).
    [Crossref]
  7. W. S. Stiles and B. H. Crawford, Proc. Roy. Soc. (London) B 112, 428 (1933); Proc. Roy. Soc. (London) B 116, 55 (1934).
    [Crossref]
  8. W. D. Wright and J. H. Nelson, Proc. Phys. Soc. (London) 48, 401 (1936).
  9. E. Brücke, Arch. Anat. u. Physiol. 11, 444 (1843); Arch. Anat. u. Physiol. 14, 387 (1847); Müllers Archiv (1847), pp. 225 and 479.
    [Crossref]
  10. G. L. Walls, “Visual Cells and their History” in Biological Symposia (Jacques Cattell Press, 1942), vol. 7, p. 203.
    [Crossref]
  11. B. O’Brien, J. Opt. Soc. Am. 36, 506 (1946); J. Opt. Soc. Am. 37, 275 (1947).
    [Crossref]
  12. G. Toraldo di Francia, J. Opt. Soc. Am. 39, 324 (1949).
  13. B. O’Brien, J. Opt. Soc. Am. 39, 324 (1949).
  14. J. N. Jean and Brian O’Brien, J. Opt. Soc. Am. 39, 12 (1949).
  15. B. O’Brien, J. Opt. Soc. Am. 40, 11 (1950).
    [Crossref]
  16. F. Flamant and W. S. Stiles, J. Physiol. 107, 187 (1948).
  17. G. Toraldo di Francia, Proc. Phys. Soc. (London) B 62, 461 (1949).
  18. S. Hecht, “Energy Relations in Vision” in Biological Symposia (Jacques Cattell Press, 1942), vol. 7, p. 1.
    [Crossref]
  19. G. Wald and H. deVries, Nature 158, 303 (1946).
    [Crossref] [PubMed]
  20. M. H. Pirenne, Proc. Cambridge Phil. Soc. 42, 78 (1945).
  21. A. Rose, J. Opt. Soc. Am. 38, 196 (1948).
  22. B. O’Brien and E. D. O’Brien, J. Opt. Soc. Am. 38, 1096 (1948).

1950 (1)

B. O’Brien, J. Opt. Soc. Am. 40, 11 (1950).
[Crossref]

1949 (4)

G. Toraldo di Francia, Proc. Phys. Soc. (London) B 62, 461 (1949).

G. Toraldo di Francia, J. Opt. Soc. Am. 39, 324 (1949).

B. O’Brien, J. Opt. Soc. Am. 39, 324 (1949).

J. N. Jean and Brian O’Brien, J. Opt. Soc. Am. 39, 12 (1949).

1948 (3)

F. Flamant and W. S. Stiles, J. Physiol. 107, 187 (1948).

A. Rose, J. Opt. Soc. Am. 38, 196 (1948).

B. O’Brien and E. D. O’Brien, J. Opt. Soc. Am. 38, 1096 (1948).

1947 (1)

1946 (2)

1945 (1)

M. H. Pirenne, Proc. Cambridge Phil. Soc. 42, 78 (1945).

1936 (1)

W. D. Wright and J. H. Nelson, Proc. Phys. Soc. (London) 48, 401 (1936).

1933 (1)

W. S. Stiles and B. H. Crawford, Proc. Roy. Soc. (London) B 112, 428 (1933); Proc. Roy. Soc. (London) B 116, 55 (1934).
[Crossref]

1928 (1)

S. Hecht, J. Gen Physiol. 11, 255 (1928).

1915 (1)

P. W. Cobb, Am. J. Physiol. 36, 335 (1915).

1843 (1)

E. Brücke, Arch. Anat. u. Physiol. 11, 444 (1843); Arch. Anat. u. Physiol. 14, 387 (1847); Müllers Archiv (1847), pp. 225 and 479.
[Crossref]

Brücke, E.

E. Brücke, Arch. Anat. u. Physiol. 11, 444 (1843); Arch. Anat. u. Physiol. 14, 387 (1847); Müllers Archiv (1847), pp. 225 and 479.
[Crossref]

Cobb, P. W.

P. W. Cobb, Am. J. Physiol. 36, 335 (1915).

Crawford, B. H.

W. S. Stiles and B. H. Crawford, Proc. Roy. Soc. (London) B 112, 428 (1933); Proc. Roy. Soc. (London) B 116, 55 (1934).
[Crossref]

deVries, H.

G. Wald and H. deVries, Nature 158, 303 (1946).
[Crossref] [PubMed]

Flamant, F.

F. Flamant and W. S. Stiles, J. Physiol. 107, 187 (1948).

Hartridge, H.

H. Hartridge, Recent Advances in the Physiology of Vision (The Blakiston Company, Philadelphia, 1950).
[Crossref]

Hecht, S.

S. Hecht, J. Gen Physiol. 11, 255 (1928).

S. Hecht, “Energy Relations in Vision” in Biological Symposia (Jacques Cattell Press, 1942), vol. 7, p. 1.
[Crossref]

Higgins, G.

Jean, J. N.

J. N. Jean and Brian O’Brien, J. Opt. Soc. Am. 39, 12 (1949).

Jones, L. A.

Nelson, J. H.

W. D. Wright and J. H. Nelson, Proc. Phys. Soc. (London) 48, 401 (1936).

O’Brien, B.

B. O’Brien, J. Opt. Soc. Am. 40, 11 (1950).
[Crossref]

B. O’Brien, J. Opt. Soc. Am. 39, 324 (1949).

B. O’Brien and E. D. O’Brien, J. Opt. Soc. Am. 38, 1096 (1948).

B. O’Brien, J. Opt. Soc. Am. 36, 506 (1946); J. Opt. Soc. Am. 37, 275 (1947).
[Crossref]

O’Brien, Brian

J. N. Jean and Brian O’Brien, J. Opt. Soc. Am. 39, 12 (1949).

O’Brien, E. D.

B. O’Brien and E. D. O’Brien, J. Opt. Soc. Am. 38, 1096 (1948).

Pirenne, M. H.

M. H. Pirenne, Proc. Cambridge Phil. Soc. 42, 78 (1945).

Polyak, S.

S. Polyak, The Retina (University of Chicago Press, Chicago, 1941).

Rose, A.

Stiles, W. S.

F. Flamant and W. S. Stiles, J. Physiol. 107, 187 (1948).

W. S. Stiles and B. H. Crawford, Proc. Roy. Soc. (London) B 112, 428 (1933); Proc. Roy. Soc. (London) B 116, 55 (1934).
[Crossref]

Toraldo di Francia, G.

G. Toraldo di Francia, Proc. Phys. Soc. (London) B 62, 461 (1949).

G. Toraldo di Francia, J. Opt. Soc. Am. 39, 324 (1949).

Wald, G.

G. Wald and H. deVries, Nature 158, 303 (1946).
[Crossref] [PubMed]

Walls, G. L.

G. L. Walls, “Visual Cells and their History” in Biological Symposia (Jacques Cattell Press, 1942), vol. 7, p. 203.
[Crossref]

Wright, W. D.

W. D. Wright and J. H. Nelson, Proc. Phys. Soc. (London) 48, 401 (1936).

Zoethout, W. D.

W. D. Zoethout, Pysiological Optics (Professional Press, Chicago, 1927).

Am. J. Physiol. (1)

P. W. Cobb, Am. J. Physiol. 36, 335 (1915).

Arch. Anat. u. Physiol. (1)

E. Brücke, Arch. Anat. u. Physiol. 11, 444 (1843); Arch. Anat. u. Physiol. 14, 387 (1847); Müllers Archiv (1847), pp. 225 and 479.
[Crossref]

J. Gen Physiol. (1)

S. Hecht, J. Gen Physiol. 11, 255 (1928).

J. Opt. Soc. Am. (8)

J. Physiol. (1)

F. Flamant and W. S. Stiles, J. Physiol. 107, 187 (1948).

Nature (1)

G. Wald and H. deVries, Nature 158, 303 (1946).
[Crossref] [PubMed]

Proc. Cambridge Phil. Soc. (1)

M. H. Pirenne, Proc. Cambridge Phil. Soc. 42, 78 (1945).

Proc. Phys. Soc. (London) (2)

G. Toraldo di Francia, Proc. Phys. Soc. (London) B 62, 461 (1949).

W. D. Wright and J. H. Nelson, Proc. Phys. Soc. (London) 48, 401 (1936).

Proc. Roy. Soc. (London) (1)

W. S. Stiles and B. H. Crawford, Proc. Roy. Soc. (London) B 112, 428 (1933); Proc. Roy. Soc. (London) B 116, 55 (1934).
[Crossref]

Other (5)

G. L. Walls, “Visual Cells and their History” in Biological Symposia (Jacques Cattell Press, 1942), vol. 7, p. 203.
[Crossref]

W. D. Zoethout, Pysiological Optics (Professional Press, Chicago, 1927).

S. Polyak, The Retina (University of Chicago Press, Chicago, 1941).

H. Hartridge, Recent Advances in the Physiology of Vision (The Blakiston Company, Philadelphia, 1950).
[Crossref]

S. Hecht, “Energy Relations in Vision” in Biological Symposia (Jacques Cattell Press, 1942), vol. 7, p. 1.
[Crossref]

Cited By

OSA participates in Crossref's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (17)

Fig. 1
Fig. 1

Visual acuity as function of pupil diameter (Cobb, best observer).

Fig. 2
Fig. 2

Visual acuity as function of luminance (Koenig, from Hecht).

Fig. 3
Fig. 3

Visual acuity as function of distance from fixation point (Jones and Higgins).

Fig. 4
Fig. 4

Longitudinal section of human eye (Zoethout).

Fig. 5
Fig. 5

Longitudinal section of central macula of human eye (Polyak).

Fig. 6
Fig. 6

Photomicrograph of adult human fovea (mag 490 ×). Plane of section cuts through outer segments of central foveal cones and through inner segments of cones surrounding center.

Fig. 7
Fig. 7

Photomicrograph of adult human fovea. Same section as Fig. 6. but at higher magnification (mag. 1000 ×) and centered near margin of Fig. 6.

Fig. 8
Fig. 8

Photomicrograph of adult human fovea. Showing center (mag. 1000 ×) section a few microns nearer front of eye than Figs. 6 and 7, cutting through inner segments of central cones.

Fig. 9
Fig. 9

Cones from the human eye (walls). 9A. Typical extra-macular cone. 9B. Rod cell near margin of macula.

Fig. 10
Fig. 10

Idealized drawing of an average foveal cone of human eye.

Fig. 11
Fig. 11

Relatively visual effectiveness of flux through unit area of pupil as function of distance of area from pupil center. Curves are from geometrical theory neglecting diffraction. Points are visual observations by Stiles.

Fig. 12
Fig. 12

Model cones of polystyrene foam for electric wave tests.

Fig. 13
Fig. 13

Electric wave test of geometrical theory including diffraction. Full lines are visual observations by Stiles and Crawford. Points and dotted lines are electric wave measurements on cone models.

Fig. 14
Fig. 14

Idealized diagram of cones in fovea showing light trapping.

Fig. 15
Fig. 15

Flamant and Stiles results for Stiles and Crawford effect of observer with retinal elements apparently tilted.

Fig. 16
Fig. 16

Photomicrograph of rabbit retina prepared by quick freezing technique (Mag. 490 ×).

Fig. 17
Fig. 17

Arrangement for ballistic stimulation tests of uniform response of foveal cones.